The objective of this proposal is the development of surrogate tissue controls for clinical immunohistochemical (IHC) assays. Presently, each clinical histology laboratory identifies, sections, validates, and archives their own tissue controls. This method is labor-intensive, non-standard, and does not detect either early reagent failure or procedure error. In the Phase I study, we developed synthetic controls for two of the most important analytes in the IHC laboratory - - estrogen and progesterone receptors (ER/PR). Our "synthetic" controls are (1) inexpensive, (2) antigen-specific, (3) available in an inexhaustible supply, (4) standardized, (5) stable, for ease of storage, and (6) quantifiable, for providing a reference standard against which to measure assay sensitivity. The Phase II specific aims include: (1) Clinical Validation, leading to FDA clearance for the ER/PR controls, and (2) Development of a complete panel of analyte controls. The first specific aim defines the product's clinical utility. The second aim is an extension of our Phase I technology. We will finish the task started in Phase I, to create a panel of synthetic controls that meet the clinical laboratories' quality control needs. These synthetic controls are a unique tool to verify proper assay performance and minimize analytic error. PROPOSED COMMERCIAL APPLICATIONS: The technology described in this grant proposal will provide the first commercially produced, standardized quality control system for clinical immunohistochemical assays. Controls are important to ensure that a patient's test result is accurate, regardless of which laboratory performs the test.